Underground Vault Fire Leaves Thousands of Long Beach Homes Without Power

An underground electrical vault fire on Broadway near Newport Avenue knocked out power to more than 26,000 Southern California Edison customers in Long Beach on Sunday evening, and as of Monday morning thousands were still sitting in the dark. The outage struck during a regional heat wave that pushed temperatures in Long Beach to 93 degrees, adding urgency to a repair effort complicated by the city's aging underground grid.

The outage was first reported at 6:40 p.m. Sunday, according to MyNewsLA.com, after the vault caught fire on Broadway near Newport Avenue in the Bluff Heights neighborhood. Edison de-energized the line following the fire, and by Monday the utility said 16,456 customers remained without power, down from an initial estimate of more than 26,000. Edison estimated at the time that power would be restored by 8 a.m. Monday, with a field investigator working to determine the necessary repairs and a repair crew on the way, per the outlet.

Separately, Southern California Edison told CBS News that the blackout affected 22,066 customers at its peak before crews reduced that number to 14,057 by 11 p.m. Sunday. The discrepancy between the two customer counts reflects separate updates released over the course of the evening as SCE crews worked to isolate the fault and restore service.

Explosions Reported Near Redondo Avenue

Eyewitness social media video reviewed by Long Beach Watchdog appeared to show two electrical transformers exploding near Redondo Avenue and Vista Street as a result of the vault fire. Long Beach fire crews closed several blocks along Broadway during the emergency response, according to the same outlet.

The outage's footprint stretched across a coastal swath of the city, with the covered area running west of Quincy Avenue, east of Alamitos Avenue, north of Ocean Boulevard, and south of Seventh Street. The Long Beach Post's neighborhood analysis found that the outage boundaries heavily impacted residents in Belmont Heights and Bluff Heights, while adjacent Belmont Shore was left unaffected — a distinction that mattered for residents trying to figure out whether they'd have air conditioning through the worst of the heat.

A Grid With a History of Vault Failures

Long Beach's subterranean electrical grid relies on a closed-loop network design that, while built to automatically reroute power during a single-line failure, forces technicians to hunt for a faulted cable through a slow, trial-and-error process of manually switching individual circuits on and off, according to Utility Dive. That design helps explain why underground vault outages in the city tend to drag on rather than resolve quickly.

The city has been here before. In July 2015, a damaged underground cable splice sparked cascading vault explosions that launched manhole covers into the air and left more than 30,000 Long Beach residents without power for up to five days, in what the Los Angeles Times described as the city's longest continuous outage in 60 years. An independent audit and internal investigation released by Southern California Edison that November found that improper system operation, inaccurate mapping, and insufficient management oversight caused those explosions, per LAist. SCE ultimately paid nearly $2 million in claims to residents and local businesses affected by that outage.

The fallout from 2015 also drew in state regulators. The California Public Utilities Commission opened a formal enforcement proceeding against Southern California Edison and ordered an extraordinary 30-day inspection of the city's entire underground electrical system, according to the Long Beach Post's 2016 reporting on the case. State regulators retain the authority to issue substantial daily fines for system management violations.

Heat Adds Stress to Aging Vaults

Sunday's fire coincided with citywide heat alerts and the operation of municipal cooling centers as the region baked under the heat wave, per CBS News. Southern California Edison has said during past summer heat waves that prolonged ambient heat creates severe thermal stress on closed underground vaults, causing components to overheat and fail at elevated rates — a problem worsened by the fact that subterranean vaults lack natural airflow, making heat dissipation difficult during extended hot spells.

The scale of the underlying maintenance challenge is significant. In safety filings submitted to state regulators, Southern California Edison disclosed that roughly 60% of the underground electrical vaults it inspects require repair, and the utility has identified vault failures as its third-highest operational risk factor, according to LAist. SCE maintains a triennial inspection program covering more than 170,000 underground vaults across its service territory, though it remains an open question whether long-term capital upgrades have adequately modernized Long Beach's aging underground grid more than a decade after the 2015 crisis.